Determining the volume of air inside a ballonet of an airship is critical to flight safety and meeting FAA requirements for monitoring vehicle heaviness on transport airships. Traditional means of determining ballonet state on airships and aerostats are crude at best, relying upon crew members' visual inspection of the ballonet with few points of reference. The assessment is based upon the skill and experience of the crew. This approach lacks reliability and accuracy because of both, the difficulty in assessing the changes in volume and the visual interference that is encountered by the crew.
Accordingly, the conventional method is not capable of determining the volume of air in the ballonet with enough reliability and accuracy to satisfy potential FAA concerns. The conventional method lack reliability, automation, and is not capable of communicating with a flight control system.